Comparison

Adopt vs EarthPi

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Adopt

Access real-time data from autonomous oceanographic floats that record seismic activity. View instrument locations, trajectories, and health parameters. This app provides a low-cost method for oceanic data collection.

Highlights
  • View MERMAID instrument locations
  • Access recent trajectories
  • Obtain ocean depth information
  • View instrumental metadata
  • Identify instruments by name and institution
Features
Read full description

Adopt-A-Float allows users to access trajectory metadata and state-of-health parameters of the EarthScope-Oceans MERMAID fleet. MERMAID, short for Mobile Earthquake Recording in Marine Areas by Independent Divers, is a long-lived drifting autonomous float equipped with a hydrophone capable of recording acoustic waveforms generated by distant earthquakes. Most earthquakes occur at or near plate boundaries, yet most seismic monitoring stations are on dry land. Deployed but not recovered, telemetering data in near-real-time, MERMAIDs are uniquely positioned as a low-cost alternative for geophysical and environmental oceanic data collection. Diving down to a typical parking depth of 1500 m below the ocean surface, they passively drift with the ocean currents, recording the ambient acoustic wavefield, identifying earthquake signals, and surfacing to report those, on average every 4-7 days with the current settings, which are expected to give them a five-year life span. When at the surface, MERMAID collects GPS location and time information and communicates with the IRIDIUM satellite constellation using RUDICS. Using this iOS app you can: View the current location of all MERMAID instruments View their most recent trajectories and obtain information about ocean depth View instrumental metadata such as battery level and instrument pressure readings Identify the instruments by name and by operating institution Developed by Tenzing Sherpa ©2021 by Frederik J Simons (www.frederik.net) Let us know what you think! Give us feedback via https://github.com/tenzingsherpaa/AdoptAFloat-3.0/issues We acknowledge support from the U.S. National Science Foundation (www.nsf.org) under grants OCE-1917058 and EAR-1150145 (CAREER), and from Princeton University. MERMAID was designed by scientists and engineers and is now built by OSEAN SAS (www.osean.fr), from which it is commercially available. EarthScope-Oceans (www.earthscopeoceans.org) is an organization founded by a multidisciplinary group of geoscientists who are coordinating efforts to create a global network of sensors that monitor the Earth from within the oceanic environment. As other organizations are doing for the land-based seismological communities today, EarthScope-Oceans shepherds national projects into the international arena where globally relevant, applicable, and mutually agreed-upon decisions can be made on instrument development, science objectives, data management, and outreach.

About

EarthPi

Explore Earth with 27 interactive map projections. Visualize the planet from different angles, adjust time to see sunlight, and track celestial bodies. Save your discoveries with screenshot functionality.

Highlights
  • 27 Earth projections
  • Smooth projection transitions
  • Time control for sunlight simulation
  • Celestial tracking (sun and moon)
  • Screenshot functionality
Features
Read full description

EarthPi is a unique app designed to provide users with a detailed and interactive way to explore Earth through various map projections. With 27 distinct Earth projections, the app allows users to study and visualize the planet from multiple perspectives. Key Features: - 27 Earth Projections: Choose from a variety of Earth's map projections. - Smooth Projection Transitions: Switch between projections seamlessly with fluid animations and learn how each map projection works. - Time Control: Adjust the time to observe the dynamic interaction of sunlight with Earth’s surface across all projections. - Celestial Tracking: View the real-time positions of the sun and moon based on the selected time. - Screenshot Functionality: Capture and save images of any map projection. Future Development: The developer is dedicated to expanding EarthPi’s capabilities, with plans to introduce additional projections, features, and improvements.

Screenshots

Adopt3 screens
EarthPi4 screens

Verdict

The call

The clearest difference is rating: Adopt at 5.0 against EarthPi's 4.4. Adopt also leads on in-app purchases (none vs 1) and review sentiment (100% vs 67%). EarthPi's advantage is update cadence (every 3 months vs every 40 months) and ratings volume (14 vs 1). On price, ads and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. EarthPi sells 1 one-off in-app purchase. Adopt asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Adopt holds the better App Store score, 5.0 against 4.4. That said, the two scores are not equally well evidenced: EarthPi has 14 ratings behind it against 1, so its average is the more settled of the two. Written reviews point the same way: 100% of Adopt's written reviews are positive against 67% of EarthPi's.

UpkeepUpdate frequency

Adopt ships an update every 40 months, EarthPi every 3 months. The most recent releases landed on October 12, 2026 and October 15, 2026 respectively.

Scorecard7 real differences · 3 level
Adopt versus EarthPi: the parameters behind the verdict, then further details
ParameterAdoptEarthPi
PriceFreeFree
Rating5.0 (1 ratings) — better4.4 (14 ratings)
Positive reviews100.0% of reviews — better66.7% of reviews
Number of ratings114 — better
Update frequencyEvery 40 monthsEvery 3 months — better
AdsNoNo
In-app purchasesNo — betterYes
MonetizationFree — betterFree with in-app purchases
DevicesiPhone, iPadiPhone, iPad, iPod — better
Requires iOS17.512.0 — better
Further details — not scored
Size1 MB116 MB
Age rating4+4+
DeveloperFrederik SimonsOthman Alzahrani

Customer experience

Adopt

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews1 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

EarthPi

All ratings14 ratings
Positive85.7%
Neutral0.0%
Negative14.3%
Written reviews3 reviews
Positive66.7%
Neutral0.0%
Negative33.3%

In-app purchases

None

Adopt

No in-app purchases

1 purchases

EarthPi

One-time1
  • EarthPi Premium$3.99

Questions

Is Adopt free?
Adopt is free to download, with no in-app purchases.
Is EarthPi free?
EarthPi is free to download, with in-app purchases available.
Which has better reviews, Adopt or EarthPi?
Adopt is rated higher. Adopt averages 5.0 out of 5 from 1 ratings, while EarthPi averages 4.4 from 14 ratings.
Do Adopt or EarthPi have ads?
Neither Adopt nor EarthPi shows ads.
Which is updated more often, Adopt or EarthPi?
Adopt ships an update every 40 months, and EarthPi every 3 months. Most recently, Adopt was updated on October 12, 2026 and EarthPi on October 15, 2026.

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